It is the third acquisition in three months since CST completed is purchase of CrossAmerica's general partner, formerly known as Lehigh Gas GP.

"With the Landmark acquisition, we are gaining strong operating sites within our existing footprint, which will allow us to leverage our regional distribution and back-office efficiencies very quickly," said Kim Lubel, chairman and CEO of CST Brands.

The 22 stores around Austin and San Antonio operate under the Timewise brand and sell Shell gasoline.

CrossAmerica will purchase the 22 sites and wholesale fuel-distribution rights for $43.5 million. CST will purchase the personal property, working capital and convenience-store operations for $20.2 million. CrossAmerica will lease the stores to CST and supply fuel to the locations.

The two firms also announced their first drop-down transaction. CrossAmerica Partners has agreed to purchase 5 percent of CST Fuel Supply's wholesale-fuel business for $50.4 million. CST will receive 1.5 million newly issued CrossAmerica Partnership units as compensation for the deal.

"As we have stated previously, CST has a large group of assets that are ideal 'drop-down' assets for CrossAmerica, which could potentially provide us with steady growth for many years to come," said CrossAmerica CEO Joe Topper.